Supernova (SN 2014J) in the Cigar Galaxy (Messier 82)

In January 2014 there was a supernova, to be exact it was a Type Ia supernova in The Cigar Galaxy M82. I took the opportunity to Photo both. . .at the same time. .That’s right folks, go big or go home! So lets break down what each is real fast. . .The we can see the photo and how to do it yourself.

M82 is a “Starburst Galaxy” which is a is a galaxy undergoing an exceptionally high rate of star formation. It is 12 million light-years away in the constellation Ursa Major.

M82 was first thought to be what is called an Irregular galaxy, which is a galaxy with no distinct shape. But in 2005 scientists discovered two symmetrical spiral arms while observing images of M82 in Near-Infrared (NIR). How did they find them? They subtracted an axisymmetric exponenial disk from the images, the NIR ones. The arms are bluer than the galactic disk, which made it difficult to detect in the images as well as the surface brightness of the galaxy. We have a view of the galaxy that is nearly edge on. . 80 degrees to our view point. [1]

SN 2014J

. . . or the supernova that was discovered in January 2014. [2] Technically January 12 million years before 2014. Remember the galaxy is 12 million light years away so it took that long for the light to come here. Look at that I’m blathering again any way.

What I am proud of in my photo I ended up with a better photo than Carleton University’s Physics Observatory and they used a 14″ telescope. Never judge a telescope by it’s size! and if you are there please this is in no way shape of form of me gloating . . .no really I’m not.

Astronomer Steve Fossey of University College London was training four undergraduates (Ben Cooke, Guy Pollack, Matthew Wilde and Thomas Wright) on how to use a 14 inch telescope at the University of London Observatory. The Observatory is located in Mill Hill. North London.[3][4][5]

The Discovery was by pure chance as Fossey wasn’t looking for any supernova or anything specific, there happened to be a break in the cloudy night and was showing students how to use a CCD camera. said that “The weather was closing in, with increasing cloud, so instead of the planned practical astronomy class, I gave the students an introductory demonstration of how to use the CCD camera on one of the observatory’s automated 0.35–meter telescopes.”[4]

What the heck is a Ia supernova?

with out going into too much physics and astronomy lets look at the following. The Short end of it is this: A Type Ia supernovae occur in a binary star system (the kind with two suns orbiting each other) and one of those two stars has exhausted itself and entered into the white dwarf phase of it’s life cycle. The Other star. . not so important it can be anything from a giant to a smaller white dwarf. [6]

sounds good but to make this clear for anyone never having read or not knowing what the heck I’m talking about, a white dwarf is what’s left of a star after it’s life cycle is entering the end days (on astronomical days terms) and no longer has nuclear fusion going on. Like with the English language there are exceptions to this rule. The white dwarfs with the common carbon-oxygen make up are able to restart fusion if there is a rise in temperatures high enough to kick start that bad boy back into life.

How does this happen? Carbon-oxygen white dwarfs rotating at a low rate are physically limited to below 1.38 solar masses (M☉).[7][8] But push past this and they can re-ignite and this sometimes causes a supernova explosion to be triggered.This limit is called the Chandrasekhar mass, despite being marginally different from the absolute Chandrasekhar limit where electron degeneracy pressure is unable to prevent catastrophic collapse. The Chandrasekhar limit is the maximum mass of a stable white dwarf star. [9] The white dwarf sucks the matter off the companion star and does this gradually, versus a sudden merging. The more mass it gathers the more pressure, the more pressure the higher the temperature The general Hypothesis is that as it approached the limit the ignition temperature for carbon fusion is reached. If the dwarf merges with another star (colliding) which is a rare event, it will briefly exceed the limit and start to collapse under its weight. This rapidly rises the temperatures past the nuclear fusion ignition point. in a few seconds of this ignition a considerable portion of the matter starts runaway nuclear fusion and releases enough energy (1–2×1044 J)[10] to take apart the star via a supernova explosion.[11]

Why is this important? Because these events produce constant peak luminosity values. This happens because of the mass of white dwarfs that explode via is of uniform mass. The accretion mechanism causing the white dwarfs to have a uniform mass. The stability of these values allow scientists to measure distances to their host galaxies because of the visual magnitude of the supernovae is directly proportional to the distance.

How do we know it was a Type Ia supernovae? We can tell because they have a characteristic light curve. Graph the luminosity graph of luminosity as a function of time after the explosion. Near the time of maximum luminosity, the spectrum contains lines of intermediate-mass elements from oxygen to calcium; these are the main constituents of the outer layers of the star. Months after the explosion, when the outer layers have expanded to the point of transparency, the spectrum is dominated by light emitted by material near the core of the star, heavy elements synthesized during the explosion; most prominently isotopes close to the mass of iron (or iron peak elements). The radioactive decay of nickel-56 through cobalt-56 to iron-56 produces high-energy photons which dominate the energy output of the ejecta at intermediate to late times.[12]

This plot of luminosity (relative to the Sun, L0) versus time shows the characteristic light curve for a Type Ia supernova. The peak is primarily due to the decay of Nickel (Ni), while the later stage is powered by Cobalt (Co). Image credit Xenoforme

Bringing it full circle;

This was one of the closest supernova seen in decades and the closest of it’s type since 1972. It was of such importance that it was the subject of follow up observations from the Keck telescope at Mauna Kea Observatory, Hawaii and were able to precisely determine the location of the supernova [13] The prediscovery images where found as early as January 15th 2014 which was six days before discovery [14] SN 2014J is the subject of intense follow-up observations by astronomers worldwide,[15] including with the Hubble Space Telescope.[16]

Why the interest? Several reasons but one of the prominent ones is that the supernova was behind a large quantity of interstellar medium in m82. The supernova suffers interstellar extinction, with a reddening of at least one magnitude.[17]

Since the Type Ia supernova has a very predictable and calculable luminosity The degree of light extinction from M82 dust blocking SN 2014J reduces its value as an observational prototype for Type Ia supernovae, but makes it a powerful probe of the interstellar medium of M82.

There was a bit of research done to see if they could identify the star that caused it with archival information in hopes of learning more, but since it is a white dwarf it’s highly unlikely that they will find it.[18][19][20]

THE PICTURES!

I know I kinda went into a tizzy there trying to make sure you all understand how moments this was that I got to be a part of those that captured this image who knows maybe some researcher will be looking for information on the subject. . and since my photos are better than a few university Observatories. . .which would be a good enough reason to hire me wouldn’t it?

SN 2014J in M82 that I photographed in the high deserts of Nevada

I did this using my Celestron 6SE, and my Orion Star Shoot color camera. This was unguided and and a layer of 35, 60, and 90 second exposures. as you can tell I reached my upper limit of being unguided as the image suffered slight streaking from movement. Hey it was unguided. . did I mention it’s still better than their photo? I used a wedge and took these while in the back yard in Fernley Nevada. I also had very clear seeing conditions and as my notes mentioned it was cold and clear. The Image was processed in Photoshop to merge the images to one photo.

Not only did I get a great photo of the Cigar Galaxy, M82, but I also got a memorable event of the supernova as well! Simbad entry here

Sean Carroll, Ph.D., Cal Tech, 2007, The Teaching Company, Dark Matter, Dark Energy: The Dark Side of the Universe, Guidebook Part 2 page 44, Accessed Oct. 7, 2013, “…Chandrasekhar limit: The maximum mass of a white dwarf star, about 1.4 times the mass of the Sun. Above this mass, the gravitational pull becomes too great, and the star must collapse to a neutron star or black hole…”

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